Theater lighting control apparatus



THEATER LIGHTING CONTROL APPARATUS Filed Sept. l0, 1932 12 Sheets-Sheet 1 232 Mam Generafur ||||||||1||||l||||||| Ml I Lily- ATTORNEY March 4, 1941. s. BURKE Erm.. 2333307 j" THEATER LIGHTING CONTROL APPARATUS Filed Sept. l0, 1932 12 Sheets-Sheet 2 Disconnec Hela y l' laude M 5 TTNEY 12 Sheets-Sheet 3 March 491941. B. s. BURKE ETAL THEATER LIGHTING CONTROL APPARATUS Filed sept. 1o, 1932 lvlarfsh'll7 194L B. s. BURKE Erm; 2,2337807 THEATER LIGHTING CONTROL APPARATUS Filed sept. 1o, 1932 12 sheets-sheet 4 TTO'RNEY March 49 1941. E, s BURKE E11-AL v 2,233,807

THEATER LIGHTING CONTROL APPARATUS Filed Sept. 10, 1952 l2 Sheets-Sheet 5 ATTORNEY 1 March 4, Q. I B, 5, BURKE ETAL 2,233,807

THEATER LIGHT-ING CONTROL APPARATUS Filed Sept. 10, 1932 12 SlxeecS--Sheetl 5 l N V F NTO R5 Buff 5. ur/fe, .5 fan/e R. Awww/egg;

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THEATER LIGHTING CONTROL APPARATUS Filed Sept. 10, 1932 l2 Sheets-Shea?. 10

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l 2,233,807 THEATER LIGHTING CONTROL APPARATUS sylvania Application September 10, 1932, Serial No. 632,558

27 Claims. (Cl. F75-312) A further object of the invention is to provide a control system for theater lighting or like cir- The invention relates to control apparatus and particularly to apparatus for controlling theater lighting circuits.

An object of the invention is to provide a control apparatus for theater lighting and like circuits wherein facilities are provided for selectively presetting the lighting characteristics of a plurality of circuits for a number of effects or scenes in advance, and wherein diierent groups of lighting circuits may be energized predetermined degrecs during the selected scenes, and wherein the lighting intensities of the different circuits may be simultaneously varied proportionately from a predetermined intensity to any desired intensity of illumination.

Another object of the invention is to provide a control system for theater lighting and like circuits wherein each circuit contains a plurality of presettable current controlling elements that may be selectively connected in the circuit and wheref in a plurality oi individual control elements are provided each of which may control the said controlling elements of any desired number of selected circuits.

Another object oi the invention is to provide a control system for theater lighting and like circuits wherein the said individual control elements may be actuated individually to vary the light intensity of the circuits then associated therewith, or may be preset to effect predetermined light intensities in the said circuits, and wherein the said individual control elements are divided into sub-groups and influenced simultaneously by a sub-group control element.

A further object of the invention is to provide a control system for theater lighting and like circuits wherein the individual lighting circuits may (l) selectively placed under the inuence oi an individual control element in selected groups,

(2) or placed under the influence of a subgroup control element in selected group of groups,

(3) selectively and collectively in groups of any number placed under the influence of one of a group of group master control elements which in turn maybe lniluenced simultaneously through a voltage control element such as a grand master potentiometer for controlling the field o! the generator supplying the control current.

cuits having, the above-noted characteristics wherein the lighting circuits are controlled through the medium of a reactor and wherein the control apparatus affects the voltage of a grid f circuit of a vacuum tube, the output of which is impressed upon the control winding of the reactor.

- A further object of the invention is to provide a control system for theater lighting or like circuits wherein the control elements may be compactly arranged in such manner as to render them accessible to an operator who may be seated at a point 'remote from the stage, and wherein the control elements are arranged in a console similar to that of a pipe organ, and wherein the various control elements may be actuated selectively and individually either manually through finger operated keys, in group through foot pedals or hand operated wheels, or automatically at selected speeds through the medium of motor driven elements under the control of the operator.

A further object ofthe invention is to provide a control system for theater lighting or like circuits that is capable of producing a great variety oi.' lighting effects which may be selectively prearranged and ultimated at predetermined times, and wherein an endless variety of colors and hues may be attained by proportioning the intensities of the lighting in circuits having the primary colors, and wherein a color composed of the combined colors oi several circuits may be maintained without change of hue while being reduced or increased in intensity.

These and other objects that will be made apparent throughout the further description of the invention are attained by means of the control apparatus hereinafter described and illustrated in the accompanying drawings, wherein- Figure 1 is a wiring diagram showing a portion of representative circuits wherein features of the invention are embodied,

Fig. 2 is a wiring diagram showing a continuation of the circuits illustrated in Fig. 1,

Fig. 3 is a wiring diagram illustrating the wir-- ing connections to the master potentiometer clutches,

Fig. i is a front elevation of a console upon -which the control apparatus is mounted,

Fig. 5 is a vertical section through the console taken on the line V-V of Fig'. 4.

Fig. 6 is a top plan view oi' a portion of the operating mechanism for actuating. the master potentiometer and feeders,

Fig. 7 is a vertical section through the apparatus shown in Fig. 6 and additional apparatus, taken on the line VII-VII oi' Fig. 6,

Fig. 8 is a plan view of the apparatus shown in Fig. 7, showing a portion of the apparatus below the line XIII--XDZI thereof,

Figs. .9 and 10 are projected iront plan views of the instruments located on the front panels of the console, the instruments shown in Fig. 9 being disposed above those shown in Fig. 10,

Figs. 11 and 12 are vertical sections through the portion of the console having the instruments disclosed in Figs. 9 and 10 vtaken respectively on the lines XI-XI and XII-X1I thereof.

Referring to the drawings, the apparatus will best be described by reference to the wiring diagrams illustrated in Figs. 1 and 2 wherein a plurality of circuits are represented, the first and last of 'the series being represented in full on the left and right sides of the figures respectively, and the intermediate circuits being represented by rectangles in dash and dot lines.

Beginning at the bottom of the diagram on Fig. 2, the number I lamp or lighting circuit at the left side of the figure will be referred to specifically, it being understood that each circuit of the group is provided with similar control apparatus, and that any desired number of lighting circuits may be provided and controlled in the manner hereinafter specified. The various circuits may be provided with lamps of different color, preferably white and the three primary colors, red, blue and yellow, thus the footlights would comprise four circuits each having lamps oi' a color different from those of the remaining circuits of the group.

All o1' these lighting circuits No. l to No. 100, for example, comprise lamp circuits i3 that are supplied with current from supply feed conductors I4 and i5 through the medium of a saturated core reactor I8, having a direct current control winding I 'I that influences the reactance of the reactor to vary the voltage of the lamp circuit in response to fluctuations of the current through the control winding in a Well known manner.

The current supplied to the control winding of the reactor is controlled by a current control unit I8 such as is disclosed in the United States Letters Patent No. 2.030.801, granted to Robert D. Ross on February 11, 1936, and assigned to the assignee of this application and which comprises a three-electrode vacuum tube so associated with amplifier tubes that variations of the grid potential of the three-electrode tube causes corresponding variations in the output circuit of the ampli- :der tubes that is connected to the control winding I 'I of the reactor through conductors I9 and 2|.

In the diagrams the grid conductor that is connected to the grid of the three-electrode tube is designated by the numeral 22 and the positive and negative control circuit conductors are designated by the numerals 23 and 24, respectively, which are connected to the main direct-current generator 25, indicated at the top of Fig. 1.

In the control system illustrated, there are provided one 'hundred circuits each of which is provided with a grid circuit conductor 22, and there are thirty-six control units for controlling the various grid circuits. Facilities, to be hereinafter described, are provided for selectively placing any desired number oi grid circuits under the influence o! a selected control circuit, and in the present instance any eight circuits may thus be combined or grouped under the control of a single control unit.

Included in each lighting circuit control arc thirty-six grid circuit relays 261, 262 etc. of the over-center spring-held type having two operative positions, namely "closed position wherein two contacts W and V are closed and contacts X, Y, and Z are opened, and released position wherein contacts W and V are opened and contacts X, Y and Z are closed. Each relay is provided with an actuating coil 21.

Each of the thirty-six control units includes a normally open multi-contact relay 28 having an actuating coil 29 and a contact-supporting rod 3| having a pair of contact bars 32 and 33 for each of the one hundred circuits. When the coil is energized by momentarily closing of a cross connecting push button switch 341, 342, 3436 associated with their respective control units, the contact bars 32 and 33 'engage their respective contacts 32a and 32h connected in the circuit containing the grid circuit relay coil 2'I and will cause that coil to actuate the grid circuit relay, provided that the circuit is otherwise completed. Whether it is completed will depend on factors of control to be hereinafter described. On a panelboard hereinafter referred to as a cross-connecting panel, are mounted cross-connecting circuit switches 39, one for each circuit and designated specically as 391, 392, 39100. The switches are oi the single-pole double-throw type having its pivoted blade connected to the negative control feed conductor 24 and adapted to alternatively be `moved to closed or released positions wherein it engages the contacts 4I and 42 that are respectively connected to contacts V of the grid circuit relay 25 and one of the contacts 3221 of the multi-contact relay 28.

It will be understood that the grid conductor 22 connected to the grid of the three-electrode tube oi.' the control unit I8 may be connected through a variety of control devices interposed between the negative terminal 43 of the generator 25 and the grid terminal of the control unit I8 for the purpose of placing the control of the circuit under the control of diierent control mechanisms that may function in a variety of combinations or which may be manually or motor operated at different speeds, individually or collectively in predetermined groups.

In order to divide the controlled lighting circuits into groups and to place the grid circuits ci' the selected lighting circuits under the control of any one of the thirty-six control units. say control No. I for example, the cross-connecting circuit switches 391, 396, 3911, 3915 etc. are moved to closed" position. Therefore, the grid circuits of lighting circuits Nos. I, 6, I2 and I6 are prepared for simultaneous energizaton as a group under the control of the cross-connecting push button 341. At this time, it is assumed that the contacts W and V of the grid circuit relays 261 of each of Ithe selected circuits are closed and the contacts X, Y and Z open. The grid conductor 22 is then connected to the negative feed conductor 24 through series connected contacts V of all of the grid circuit relays 261 to 2636.

When the cross-connecting push-button switch 341 for control unit No. I is momentarily closed, the coil 29 is energized and the normally-open multi-contact bars 32 and 33 of each of the one hundred circuits to engage their respective cont v 2,233,807 tacts. This action causes energization o! the grid circuit relay coil 21 through the contact bars 32 whichcauses all oi' the relays 23' of the selected circuits associatedV with the control No. I' relay 28 to operate and open contacts W and V thereof, the circuit from the positive control feed conductor 23 being through contact -bar 32, contact 32", coil 21, conductor 45, common to the thirty-six relays oi thel circuit, conductor 46,

contact V of relay 263 and all of the remaining relays and ilnally through contact 4I VVVand the closedf cross-connecting switch 38' to the negative control conductor 24.

Energization of the coils 21 of the No. I control -units of the selected circuits of the group, as

stated above, then opens contacts W and V and closes contacts X, Y and Z of the grid circuit relays. Since the contact V'of the relay 28' is ythen open, subsequent'movement of the crossconnecting circuit switches 39 of circuits not originally selected for control unit No. I cannot be added to the selected group without again momentarily closing the cross-connecting push button switch 34. i

Since the contact V of the grid-circuit relay 26' is open. the selected circuit cannot at the same time be controlled through any other control unitsuch as No. 2 or No. 36, because the coil 21 of such relays cannot be energized so long as any one of the series related contacts V -are open.

To again close the contacts W and V the switches 39' etc. are moved to release position and when the switch 34 is again momentarily closed, a circuit is established through the coil 21 through -bus 24, connected to the negative control conductor 24, switch 39', contact 42, bus 42 common to the 36 relays 26' to 263, contacts 32b and bar 33, conductor 33, contact X, coil 21,

contacts 32'L and bar 32, bus 23Il to positive control conductor 23.

When the contact W is opened the grid circuit is transferred from contact W to contact Z, that is, connected to the bus 41' that is connected in common to all of the contacts Z of the grid circuit relays 261 of the No. I control unit. The buses 41 to 411iB are connected respectively to second busses 48' to 48118 that are connected respectively to one arm 49 of double-pole doublethrow pilot switches I1 to 5I:16 (one for each control circuit means) that are movable to n" and off" positions. When this switch is in the off position shown, the grid conductors of the associated circuits remain connected to the negative conductor 24 and cannot be influenced through other controls such as the potentiometers to be hereinafter described. y

When the pilot switch 5I1, for example, is in the on position the grid conductor is connected to the pivoted arm of a single pole double-throw selector switch 52' through conductor 53 and which is alternatively movable to "manna and pre-set positions. At this time the switch arm 54 closes a circuit through a pilot lamp 60 thus indicating that the circuit is now ready for operation. Y

With the selector switch 521 in the manual position the grid circuit includes a conductor 55 that is connected to a movable contact 56 of one of thirty-six individual control potentiometers '511, 512, 5135, one end of which is connected to a common negative bus 58 that is connected to the negative control conductor 24 and the other end of each Ibeing connected to the moving arm of a jsub-group of selector switches 581, 591, 593, 591.

581, etc. The negative bias on the grid circuit at this time is determined by the position of the arm on the potentiometer, assuming that the upper end of the potentiometers 511, 512 are connected to the positive conductor 28 through circuits including the switches 591, 581. etc.

Withthe selectorlswitch 521 in the pre-set position the grid circuit is connected through conductor 6I to protective resistor 62 to normally open relay contacts 63, 64, 65 and 66 of scene flasher relays 81, 88, 69 and 10, respectively, and to the normally closed contact 1I of the fader disconnect relay 12. The actuating coils of the relays 61, 68, 69 and 10 are connected across the positive and negative control conductors 23 and 24 respectively, through the medium of push and pull scene flasher button switches 13, 14, and 16, respectively, and the coil of the normally energized relay 12 is energized through a series of normally closed break contacts 11 connected in series relation and actuated severally by the relays 61 to 10 to open position when any of the said relays are actuated to close the contacts 63, 64, 65 and 66.

The contacts 63, 64, 65 and 66 are connected respectively to four points 63', 64', 65' and 66', respectively, of a scene fader potentiometer 18, and respectively to the movable contacts 63", 64, 65" and 66" of four pre-set potentionrneters 19, 80, 6I and 82. The contact arm 83 of the scene fader potentiometer 18 is connected to the protective resistors 62 through the medium of the contact 1 I.

'I'hus it will be seen that when the slector switch 52 is in the pre-set position the grid circuit is connected through- (-1) A preventive resistor 62, contact 1I of the fader disconnect relay 12, to the moving arm 83 oi' the scene fader potentiometer 18.

(2) Preventive resistors 62 and contacts 63 of scene flasher relay 61 for scene I, 68 for scene II, 69 for scene III and 1D for scene IV.

It will be understood that the relays 61 to 1I) and 12 comprise bars 84 that are actuated by the coils of the relays and are connected to the contacts`63 to 66, 11 and 1I, so that said contacts of all circuits are actuated simultaneously by the bars 84.

The function of the scene fader is to accomplish a gradual and proportional transition from one scene tothe next succeeding scene. This is accomplished as follows.

With the grid wire connected to the moving arm 83 of the scene fader potentiometer 18, and this arm on position 63 for scene 1, a negative potential is applied to the grid circuit depending upon the position of the movable arm 63" of pre-set potentiometer 19 for scene 1, the lower end of which is connected to the negative control feed conductor 24.

Moving the arm of the scene fader from position 631 (scene 1) to position 64' (scene 2) gradually changes the potential impressed on the grid circuit from that previously set up on preset potentiometer 19 (scene l) to that pre-set on potentiometer 80 (scene 2).

Assuming operation on scene 1 and that it is desired to transfer instantly to the scene 3 operation, upon depressing the scene flasher push button 1 5 which energizes the coil of the relay 69, the fcontact 65 thereof is instantly connected to the moving arm 65"v of the potentiometer 8I (scene 3) and the contact 11 of that relay opened, thus interrupting the circuit through it to open its contacts 1I. This last operation disconnects the grid wire from the moving arm of the fader leaving it connected through the scene flasher relay contacts 65 of thus completing, the circuit through the operat..

ing coil of the fader disconnect relay, causing it to close its contacts, thus again connecting the grid wire to the moving contact 63," of pre-set potentiometer 19. l,

To iiash from scene 3 to scene 4 pre-sets without utilizing the fader, depress scene flasher pushbutton 16 (scene 4) and pull the previously closed pushbutton 15 (scene 3). This operation closes scene flasher relay 10 and connects the grid conductor to the moving arm 56" of the pre-set potentiometer @il and disconnects it from the potentiometer ill (scene 3).

lt will be under-sto d that the resistance of the scene fader potentiometer 18 is sufficiently light to allow changing the pre-set potenn tiolneters of the scenes not in use without ef fecting a change in the scene in progress.

@o far, it has heen shown in what manner any number of circuits may be placed under the con trol of one of the thirty-six control units and the manner in which the light intensity of the selected circuits may be pre-set -for four scenes and the manner in which the control units may be individually operated at will to vary the negative grid potential on the tube control units to produce desired light intensity variations.

1t will now be shown how the thirty-six con trol units may be operated individually or in groups of four through any one` of nine subgroup potentiometers or how any number of control units may be controlled through any one of four group master potentiometers, or in what manner any one or all of the four group master potentiometers may be controlled by a grand master potentiometer which controls the generator voltage of the control circuit.

The manner in which the circuits are to be controlled is primarily dependent upon an interlocking selector switch shown in Figs. 10 and 1l (one for each of the thirty-six control units) the switch comprising an "individual switch B6, a "grand master switch 81 and four group master switches 881, 882, 883, 884. Each switch includes a normally open contact 89 and a normally closed contact 9|, the latter contact of all of the switches being connected in series relation.

The construction of the interlocking switch 85 is such that when a control button of any switch 831, 883 etc. is pushed in to close its respective normally open contact 89 and open its respective normally closed contact 9|, any other button that is then in the "in position will be forced out to its original position. It will be seen, therefore, that a circuit can be influenced by one only of the above referred to control devices at any one time.

It will be understood that the sub-group selector switches 591, 592, etc., the movable contacts of which are connected to the positive end of the individual potentiometers 511 and 512 etc., respectively, are normally in the on or closed position wherein the positive ends of the individual through negative control bus 58, potentiometer I 511 closed switch 591, conductor 92, contact I9 to the positive individual bus 83. The negative bias on the grid control conductor 55 is then dependent upon 'the position of the movable contact 56 on the potentiometer 511. If the contact 56 is at the negative end of the potentiometer,

the negative bias is maximum and the lamps of Y ythe lighting circuits are black out. The degree of illumination will therefore be dependent upon the posi-tion of the contact 50 and full illumina tion of the lamps ci the lighting circuits will be obtained when the contact 56 is near the positive end of the potentiometer 511.

Should it he desired to place selected individual control potentiometers 511, 512, etc. under the iniluence of any one of four group master potentlolneters 961, i902, M3, or 9114, for example, 941, the button of the group master switch B8' of each selected control potentiometer is depressed, closing the contact 00 thereof and opening the contact il i. This action automatically returns the "indivldual switch `B5 to its original "out position. Under this condition, fthe positive ends of the selected potentlometers are connected to the positive control conductor 23 through Athe following circuits, conductor 92, contacts 9| of interlocking switches B5 and 81, contact B9 of switch 88', group master bus 95, conductor BS', movable contact 91', group-master potentiometer 91|', normally open group master switch 58', which when closed connects the positive end of the potentiometer 9d' to the positive bus 99 connected to positive control conductor 23.

Thus all or any of the 36 potentiometers 511, 512, etc., may be connected t-o and controlled by any one of the four group master potentiometer-s 941, 942, 943 or 341 when its respective "group master switch is in fthe closed or "individual" position, wherein the positive end of the potentiometer isconnected to the positive bus 99.

The four group master potentiometers 901, 942, etc., may be selectively or collectively controlled by a grand master potentiometer |0| that -is connected across the positive and negative control conductors 23 and 24, respectively, by moving the group master switches 981, 981, 983 and 984 to the master position wherein the positive ends of the group master potentiometers 941, 942, etc., are connected to a bus |02 that is conneoted to the positive grand-master generator bus |03. The bus |03 is connected to the positive terminal |04 of the grand master generator |05 and potentiometers 941, 941, etc., are connected to a bus |02 that is connected to the positive grandmaster generator bus |03. The bus |03 is connected to the positive terminal |04 of the grand master generator |05 through bridging contact |06 of a black-out contacter switch |01, A movable contact |08 connected to the field winding |09 of the generator |05, slidably engages the potentiometer coil |0| and determines the voltage output of the generator |05, thus effecting the negative bias of the grid wires 55 that are then controlled through individual control potentiometers 511, 511,- etc., and group master potentiometers 841, 841. etc.

The ind-ividual control potentiometers 511, 811, etc., may be grouped in groups of four each and thus selectively or collectively controlled in groups of four through one of nine sub-group potentiom.

^ eters |H1, IH?, HIJ, etc., by connecting the positive ends of the potentiometers of 511, 511, 511 and 514 to potentiometer HI1, potentiometers 511, 510,1511 and 51 to potentiometer HI, etc. This is' done by moving the sub-group selector switches 581, 581, etc., of desired control potentiometers 511, 512, etc., to the sub" position, or from the normal interlock position shown in Fig. 1 to the left hand position wherein the positive ends of the potentiometers 511, 511, etc., are connected to the through conductors H2 to the movable contacts H31, I |31, etc., that slidably engage the sub-group potentiometers |||1, HI, etc., respectively, having their negative ends commonly connected to the negative bus H4 that is connected to negative control conductor 24, and having their positive ends connected to pivotal sub-group potentiometer or to switches H51, H52, H53, etc., that may be moved by the foot of the operator to connect the potentiometers direct to the positive bus H8 that is in turn connected to the positive feed conductor 23, or to a bus I I1 that is connected to the positive generator bus |03.

When the potentiometers are connected to the positive conductor 23 as in the first-mentioned instance, the grid control wire 55 is controlled through the individual potentiometers 511, 511, etc., and the sub-group potentiometers H81, H31,

etc.,l and when the individual potentiometers are connected to the positive generator bus |03, the control is extended to the grand master" generator '|05 which effects changes in voltage in the positive conductor dependent upon the position of the moving contact |08 of the grandmaster potentiometer |0| which controls the field winding of the generator. l

Thus it Will be seen that the lightingcircuits are controlled by the negative bias -imposed on a grid wire of a three-electrode tube which in turn controls an A. C. amplifier which rectiiles its output and controls a saturated core reactor.

y The negative bias of any number of grid wires may be placed nuder the control of any one of thirty-six control potentiometers, and the potential across these potentiometers may be selectively varied either through sub-group potentiometers or group master potentiometers, selectively supplied with current from either of two generators, one of which, the generator |05, effects variations in potential through potentiometer control of the field winding and the other, generator 25, effects variations in potential supplied to the contr-o1 conductors 23 and 24 through a variable resistance H8 interposed in the circuit of its field winding H8.

The switchboard apparatus containing the various control devices referred to above, comprises a console |2| of the general pipe organ type having side panels |22 and |23, a stepped front panel |24, and a lower front panel |28 as shown in'Figs. 4 and 5. Considering the circuit control devices in the order in which they were referred to above, the control switches 341 to 3438 are mounted on the front panels |24 Figs. 5 and 9, and the cross connection circuit switches 391 to 39100 are mounted 0n the side panel |22 on opposite sides of the console and adjacent their respective pilot lamps 40 which are energized when the contacts y of the relays 261 to upon momentary closure of a press button pilot lamp switch 50 on the front panel adjacent each cross connecting panel switch 341, 341, etc., what circuits are connected thereto.

Directly above the cross connecting panel swtches and on the sub-panel |28 upon which they are mounted, Figs. 9 and 1l, the "pilot switches" 5|1 to 5F1 of the control circuits are mounted. ,These switches are provided with the legends On and OIP' and when in the oiT' position, the grid conductors 22 of the circuits associated with their respective control circuits are connected directly to the negative conductor 24, as before described, and cannot be influenced by other control devices such as potentiometers, etc When the pilot switches 5Il to 0F"1 are in the "on" position, they connect the grid conductors to the single pole, double throw selector switches 5I1 to 5236 that are mounted on the sub-panel |28 and provided with the legends Pre-set and Manuai. When the selector switch" is in the manual position, the grid lconductors of the associated circuits are connected to the movable contacts 56 of their respective control potentiometers 51.1 to 5138 mounted on the sub-panel |32 Figs. 10 and l1, and when the selector switch is in the preset position, the grid conductors are connected to the scene flasher relays 61, 68,. 68 and 10, Fig. 2 that are controlled by the scene flasher push buttons" 13 to 16, Figs. 2 and 9, mounted on the center section of the sub-panel |28. The scene flasher relays are associated with the scene fader potentiometer" 18, one for each control circuit, mounted behind the front panel |24 as will hereinafter appear.

The scene fader" is associated with movable contacts 63 to 68" of the four pre-set potentiometers 18 to 82, Figs. 1 and ll, of each control circuit, which are mounted on the sub-panel |21, Figs. 9 and 11.

The thirty-six interlocking selector switches 85, Figs. 2 and 11, are mounted upon the panel |28, and may comprise a plurality of push buttons, for example, 86, which is shown in its depressed position. A rod |35 connected thereto carries a irustoconica1 cam |36 and the two switch contacts 88 and 8|, the former of which is normally open and the latter of which is normally closed. A slide bar |31, biased toward the right by a leaf spring |38 is provided with holes |38 of slightly larger diameter than the cam |36. As shown, button 86 is depressed and the spring |38 has so moved thebar |31 that the upper side of the cam |36 engages the bar. When any other button 81, 881, etc., is depressed, the cam |36 thereon displaces the bar toward the left as the cam |38 moves through the associated hole |38, and thereby releases the cam |36, permitting a spring I4I to return the button 86 to its original position. Thus, when any other button is depressed, the button will be released, etc. y

When the button 86 marked Ind for individual is depressed the grid wires of the associated circuits are controlled through the lndividual potentiometers 5.11, 512, etc., of the control circuits.

With any one of the buttons 881, 882, 883 or 884 depressed, the grid wires of the associated circuits are controlled through the ycorresponding one of the four group master potentiometers 841, 842, 8411 or 844, Figs. 3, 5 and 8, mounted behind the front panel |24, as'shown in Fig. 5 and adapted to be separately operated manually, through hand wheels |42, |43, |44 and |45, respectively. Figs. 4 and 8. which turn worms |49, geared Eto clutches |41, |48, |49 and |50, respectivelyA diagrammatically illustrated in Fig. 3.

'Ihe group master potentiometers 941, 943, 943 and 84* may be selectively, individually or collectively driven -by a motor through magnetic clutches |5|, |52, |53 and |54, respectively, which serve to connect them to a shaft |55 that is driven by a motor |56 in a manner to be hereinafter described. Double throw group master clutch switches |511, |512, |513 and |511, Figs. 3 and 10, marked W for hand wheel operation and M for motor operation, serve to control the 'energization of the magnet clutch and determine in what manner the group master potentiometers are to be operated, and the group master potentiometers may be selectively operated when the group master switches 981 to 984 are in their individual position marked Ind.

The four group master potentiometers may be selectively or collectively controlled, as previously stated by a grand master potentiometer IDI, Figs. 3, 6 and 8, by moving such group master switches 981, 983, 963 and 984, Fig. 1, to the master position, as are desired to be controlled by the grand master potentiometer. This operation places the sub-group potentiometers under the influence of the grand master generator 1|05 which varies the voltage in the circuit through varying the current conditions in the field winding of the generator.

As previously stated, the individual potentiometers 511, 513 to 513s may be grouped in groups of four each and thus selectively or collectively controlled through one of nine sub-group potentiometers |||1, |||3 to |||g by'moving the subgroup selector switches 591, 593, etc., of panel |39, Figs. 10 and 11 of desired control potentiometers, to the Sub position wherein the positive ends of potentiometers 511, 513, etc., are connected through conductor I|2 to the variable contacts I 81, H91, etc., that slidably engage the sub-group potentiometers |||1, H13, etc. These sub-group potentiometers may be controlled in turn by the grand master potentiometer |0| which controls the voltage of the generator |85, by means of the sub-group potentiometer toe switches ||51, H51, to H53, Figs. 1 and 4 and 5 which either connect the positive ends of the sub-group potentiometers to the positive control conductor 23 direct, or to the positive terminal of the generator |05.

A house master potentiometer |58 is mounted for operation by the motor driven shaft |55 when connected thereto by a magnet clutch |59 and for operation by a hand wheel I9| which turns a worm |92 that drives a magnet clutch |63 which connects house master potentiometer to the hand wheel drive. The motor and hand wheel clutches |59 and |63, respectively, are controlled by a double throw switch |64 in the panel |29 having motor and wheel positions having the legends M and W, respectively.

The grand master potentiometer 0| is mounted for operation by the motor driven shaft |55 when connected thereto by a magnet clutch |95, Figs. 3 and 6. and for operation by a grand master hand wheel |69 which turns a worm |61 that drives a magnet clutch |69 which connects the grand master potentiometer to the hand wheel drive. The motor and hand wheel clutches |55 and |48, respectively, are controlled by a double throw switch |69 having motor and wheel positions having the legends M and W, respectively.

'I'he house master potentiometer |58, group master potentiometers 941, 943, 943 and 944 and the grand master potentiometer |0| are adapted to be operated by means of foot pedals |121, |121, |123, |12* and |18, respectively, pivoted on the console as indicated in Figs. 7 and 8 and connected to the potentiometers through linkage |14 and |15 and rods I19yhaving loop chains |11 engaging a pinion |18 on the potentiometers in the usual manner. The potentiometers may'be rotated in both directions by rocking the foot pedals.

The sub-group potentiometers |||1 to are adapted to be operated by pivotally mounted foot pedals |8| to |89, Figs. 4 and 5, through the medium of the linkage |9| and the rods |92 which are provided with'loop chains |93 that encircle the pinions |94 which are connected to the sub-group potentiometer as previously stated, four control circuits may be selectively or collectively controlled by means of one of the subgroup potentiometers.

The scene fader potentiometers 18, thirty-six in number, are disposed on opposite sides of a scene fader drive-shaft |95, Figs. 6 and 7, that is adapted. to be connected to a motor-drive to be hereinafter described, by means of a magnet clutch |96 or to be connected to the grand master hand wheel |69 by a magnet clutch |98. Also a scene fader hand wheel |91, Figs. 4 and 8, is permanently connected to the shaft |95 by a bevel gear |99 that is driven by a pinion 20|, and a driving rod 202 provided with universal joints 203, Figs. 6 and 8.

The scene fader potentiometers 18 are mounted in a frame 204 on the upper rear portion of the console |2I, and the movable contact arms 83, Fig. 2, of each are provided with a gear 205 that meshes with a gear 286 on the scene fader drive shaft |95 as shown in Figs. 6 and 1. Rotationof the shaft |95 causes rotation of the scene fader contact arms 83 to any desired position. When it is desired to move the scene fader contact arms at a very slow rate, the clutch |99 is energized by moving the double-throw scene fader switch 201 on the panel 209, Fig. 9, to the W or grand master hand wheel position, thus establishing a driving connection between the scene fader shaft |95 and the hand wheel |66. To drive the scene fader shaft |95 by motor, the switch 201 is moved to M position wherein the magnet clutch |98 is energized, thus connecting the shaft |95 to a motor drive to be hereinafter described.

As indicated in Figs. 6, '7 and 8, the grand master hand wheel |69 is connected to the magnet clutch |98 by means of a chain 209 that meshes with pinions 2|| and 2|2 on the worms |61 and 2|3 respectively, the latter meshing with a worm wheel 2|4 fixed to the clutch |98.

Referring to Figs. 5, 6, '7 and 8, the motor drive for the group and grand master potentiometer shaft |55 and the scene fader drive shaft 95 comprises a motor |56 mounted upon a base 246 of the console 12|, that drives two gears 2|1 and 2|8 at different speeds through Aa gear train 2|9 and 22| connected to the motor by a belt 222. For example, the gear 2 1 has a 1 to 600 ratio with the motor and is termed the high speed gear, and the gear 2|8 has a 1 to 5700 ratio with the motor and is termed the low speed gear. As no claim is made to the specific form of gear train employed, the train is not illustrated in detail, nor is it more minutely described.

The high speed gear 2|1 is connected to thel selector clutch switch 228 having Fast and Slow positions for selectively energizing the clutches to obtain a desired driving speed for the shafts |55 and |95.

The control for the driving motor |55 is not shown in the diagram, Figs. 1 and 2, but may have l any preferred form of speed control regulated by a rotary control handle 229 on the panel |29,\Fig. 10. Therefore, any desired driving speeds may be obtained for shafts |55 and |95 within certain limits.

Referring now to the motor-generator apparatus, Fig. 1, the main generator 25 and the grand master generator |05 are driven by motor 23| supplied with current from a feed circuit 232 having a main contactor switch 233 actuated by a magnet coil 234 that is energized vthrough the medium of the starting contactor switch 235 having a magnet coil 236 connected across the positive and negative control conductors 23 and 24 respectively and controlled by a starting switch 231 that is so connected to a black-out switch 238 by a rocking-beam 239 that when one switch is vclosed the other is opened. The switch 238 controls the magnet winding 239 of the blackout" contacter switch |08, which in turn controls the circuits supplied by the generators 25 and |05. A battery 24| normally energizes the control circuits 23 and 24 and supplies current to the winding 235 for actuating the starting contactor switch 235.

Operation To start operation, all potentiometers and the generator rheostat ||8 may be set to effect full brilliancy, except those potentiometers 'of each circuit that are preset for effecting predetermined light intensities for different scenes, or those potentiometers that control circuits in which other than full brilliancy is desired.

The starting switch 231, Figs. 1 and 10, is rst moved to on position, thereby energizing the starting contacter switch 235 and causing the main contacts to close. This starts the motor 23|, which drives the generator 25 and |05, thus energizing the control circuits.

Assuming that it is desired to place any eight lighting circuits on a single control circuit means, for example, control No. 1

First-Move the selected eight cir-cuit switches 391, 392, 396, etc., on the cross connecting panel |22 to the close position.

Second.-Momentarily press cross connecting panel push button switch 341 for control circuit No. 1, energizing winding 29 of the multi-contact relay 28, thereby closing the eight grid relays 21 of the circuits completed by the eight closed circuit switches 391, etc.

Closing of the grid relays sets or prepares circuits through cross connecting panel pilot lamps 40, so that they indicate the connected circuits when the pilot lamp switch 50 of control circuit No. l is closed momentarily.

Th'rd.-Determine whether circuits on control No. l are to be controlled individually by circuit No. 1, control potentiometer 511 or grand master potentiometer |0| or one of the four group potentiometers 941 to 944, or its respective sub-group potentiometer actuated by foot pedals.

Fourth.-If it is determined that the circuits are to be controlled by the individual control potentiometer No. 511,

A.-Press down the individual button 85 marked (Ind.?) on the interlocking selector switch group 85.

B.-Det'ermine whether to be operated manually or by preset.

C If determined to operate by preset, the selector switch 521 is moved to preset position.

D.-If determined to operate manually and individually-the selector switch 521 is moved to manual position.

E.-To finally complete the circuit, the pilot switch 5| is moved to on or closed position.

If it is desired to operate manually as in paragraph D with the selector switch 521 in the manual position,

No. 1 control circuit individual potentiometer 511 may be operated and the eight selected circuits may be brought from black-out to full bright as desired by moving the movable contact 56 thereof that is connected to the grid conductor.

of the No. circuit, (mounted for motor or hand wheel operation) is turned either manually or by motor to the scene position as indicated by preset indicator dial 242.

The indicator arm is actuated by a volt meter and a rheostat 243 having a contact arm 244, varies voltage in the meter in accordance with the position of the feeder arm.

Third- Move selector switch 52 to preset position.

The eight selected circuits for scene will be energized in accordance with the preset slider button position on the preset potentiometers.

The circuits may be manually varied if desired during a scene by moving the preset slider buttons. .1,

To fade or blend the lighting effect of scene one to that set for scene two, manually- (a) The scene fader hand wheel |91 which is lconnected to the scene fader drive shaft at all times, is rotated, or

(b) The scene selector switch 201, Figs, 3 and 9 is moved to the W or wheel position, thereby connecting the scene fader drive shaft to the grand masters hand wheel |66 by means of the magnet clutch |38.

All circuits connected to the No. I control circuit will be slowly effected by movement of the grand master hand wheel which turns the fader drive shaft at a slower speed than the hand wheel |91, it requiring about twelve turns of the grand master hand wheel to cause one revolution of the fader arm. Therefore, the grand master hand wheel is used to obtain very gradual changes in light intensities of the associated circuits.

The lighting circuits associated with the No. I control circuit may be influenced at this time. if desired by either the preset potentiometers 19, 80,

8| and 82 or the individual potentiometer 81', depending on the position of the selector switch 52.

To obtain motor operation of the scene fader drive shaft- First-Determine the speed of scene fader operation desired, by moving the speed selector clutch switch 228 to the fast" or slow" position and a fast or slow speed will result. The fast and slow magnet clutches 223 and 225 on the shaft |55 continually operate at fast and slow speeds respectively and when energized connect the clutches to the shaft |55, depending upon the positionof the scene fader. 'Ihe shaft Il! is connected through sprockets and a chain 221 to the motor drive fader clutch |88, and consequently the latter clutch is driven, at a speed corresponding to that at which the shaft |55 is driven by the fast and slow clutches'223 and 225, respectively,

Sec0nd.-Move scene fader switch 281 to M poI sition which energizes the magnetic clutch |88 and connects the scene fader drive shaft to the motor drive.

Third-Move motor reversing switch 285 to F position for forward operation, or to R for reverse operation, as desired.

Fourth-Stop the scene fader by moving the scene fader selector switch to the oil'" or vertical position, thus de-energizing the magnet clutch |98. To stop the motor, move the motor switch 245, Fig. 10, to control'or neutral position.

In order to flash from one scene to another without fading through the successive scenes, and assuming that it is deseired to obtain the illumination preset for scene I, regardless of the scene fader position- First.-Press scene flashover button No. 1I on the center of -the panel |28, Fig. 9, which connects scene No. Flashover relay 61 in circuit, thereby operating the relay and opening the scene fader arm by opening the fader cut-out switch 1| as previously described.

Secondi-To flash to any other scene press corresponding scene fiashover button 13 to 16 and pull out the previously closed button. The setting for the selected scene will then control the associated light circuits.

Returning now to the second above mentioned alternative method of control for the circuits associated with a control circuit, namely, control by the grand-master potentiometer- First-Press down the grand master button 81 of the interlocking switch 85.

Second-Determine whether to be under preset control or individual manual control- (a) If individual control-The individual potentiometer must be set for maximum light intensity required in the circuits governed by that control circuit.

(b) If determined to operate under preset, the preset buttons 63 to 66 for the four scenes will be preset as desired.

Third.-Move pilot switch 5|, for No. control circuit on panel |25 to on" position to complete setting up of that control circuit.

Fourth-Operation of the grand master potentiometer will effect all connected circuits by varying the field current of the grand master generator and thus effects the light intensity of all of the then energized circuits. The illumination will start at the brilliancy determined by -determine the manner of operation of the presets if all of the resistance of the grand masters is out.

As the field current is varied to reduce the voltage of the control circuit, the brilliancy will diminish correspondingly from the brilliance initially determined by the preset potentiometers.

Fifth-Since the grand-master potentiometer may be operated by foot pedal at all times, and by motor or by hand wheel, determine what method of operation is desired.

(A) If determined to operate by hand wheel, throw grand-master switch |88, panel |28, Fig. 10 to W or wheel position, thereby connecting the grand-master hand wheel to the grand-master potentiometer through the magnet clutch |68, Fis. 3.

(B) If determined to operate grand-master potentiometer by the motor,

D or down-position if it is desired to I diminish the illumination.

Sixth-#To stop the grand-inastcr potentiometer, move .the grand-master switch |68 to ver tical position.

Seventh.-Since the grand-master potentiometer is connected to a foot pedal |10 at all times, it may be actuated at will by rocking the pedal with the foot.

Referring now to the third previously mentioned alternative method of controlling the lighting circuits associated with a control circuit, namely, by the group-master potentiometers which may be operated by hand-wheel, footpedal or motor.

First-Select a group-master, say No. and

groupmaster potentiometer.

(A) Press down button 881 in interlocking switch 85, panel |29, Fig. l0, thereby connecting the group-master potentiometer to any control circuits in which No. i

\ group-master key' is pressed down.

Seconds-Determine whether to be under preset control or individual manual control.

(A) If individual manual control, the individual potentiometer 511 must be set for maximum light intensity required in the circuits governed by that control circuit and the switch 98 is then moved to ind or independent position.

Third.-If determined to control, the

perate under preset 

